Energy Storage Section Research Articles

Performance improvement of liquid air energy storage: Introducing Stirling engine and solar energy

Liquid air energy storage (LAES) is a promising energy storage system with the main advantage of being geographically unconstrained. The efficiency of LAES could be improved by utilizing compression heat and integration with other systems. As an effective heat recovery process, the Stirling engine (SE) is introduced to the LAES system. The Pseudo Stirling model and Malmo relation are used to obtain practical results. Firstly, the Stirling engine is used to utilize compression heat, in which the Round Trip Efficiency (RTE) could be improved by 3.16% points and 8.96% points in LAES-SE and Liquified Natural Gas (LNG)-LAES-SE systems. Then, with solar energy introduced as heat source for the Stirling engine and air before the expander as heat sink, a more flexible Solar-LAES-SE system with decoupled charging and discharging sections is proposed. The RTE and exergy efficiency of the Solar-LAES-SE system are studied and compared with those in a Solar-LAES-Organic Rankine Cycle (ORC) and an LAES system directly heated by Solar energy. The exergy analysis shows that it is more effective to directly heat the air before expanders by solar energy than to integrate an ORC or a Stirling engine if the solar energy is insufficient. The Solar-LAES-SE systems show the best performance in terms of RTE when the air temperature before expanders is low and the molten salt (solar energy carrier) outlet temperature is high. The cost evaluation of the solar energy storage section shows that when the molten salt outlet temperature is lower than 370 °C, the cost of the molten salt-based storage system for the Solar-LAES-SE will be lower than the cost of the thermal oil-based storage system for Solar-LAES-ORC. The reason is a reduced flowrate of molten salt for decreased outlet temperature, thereby increasing temperature change for the molten salt. With a fixed duty of the heat transfer, this reduces the flowrate of molten salt. As a result, the cost of molten salt and its storage is reduced.

Review of electric vehicle energy storage and management system: Standards, issues, and challenges

Renewable energy is in high demand for a balanced ecosystem. There are different types of energy storage systems available for long-term energy storage, lithium-ion battery is one of the most powerful and being a popular choice of storage. This review paper discusses various aspects of lithium-ion batteries based on a review of 420 published research papers at the initial stage through 101 published research articles that have been finally reviewed. This review paper focuses on several topics, including electrical vehicle (EV) systems, energy management systems, challenges and issues, and the conclusions and recommendations for future work. EV systems discuss all components that are included in producing the lithium-ion battery. The energy storage section contains the batteries, super capacitors, fuel cells, hybrid storage, power, temperature, and heat management. Energy management systems consider battery monitoring for current and voltage, battery charge-discharge control, estimation and protection, cell equalization. This paper's challenges and issues discuss some of the critical aspects of lithium-ion batteries, including temperature and safety, life-cycle and memory effects, environmental effects, and recycling processes. The conclusion and recommendation of this paper indicate the future scope of research. This review paper can provide the lithium-ion battery's insight, overall synopsis and contribution, and further research directions to the EV system.

Study on the Meso‐Energy Damage Evolution Mechanism of Single‐Joint Sandstone under Uniaxial and Biaxial Compression

Energy conversion and release occur through the entire deformation and failure process in jointed rock masses, and the accumulation and dissipation of rock mass energy in engineering can reveal the entire process of deformation and instability. This study uses PFC2D to carry out numerical simulation tests on single‐joint sandstone under uniaxial compression and biaxial compression, respectively, and analyse the influence of joint inclination, length, and confining pressure on the meso‐energy conversion process and phase evolution of jointed sandstone. Through analysis, it is found that the input meso total strain energy is transformed into meso dissipated energy and meso‐elastic strain energy. Macroscopic and microscopic joint sandstone law is consistent with the overall energy evolution; and the difference is reflected in two aspects: (1) the microlevel energy evolution has no initial compaction energy consumption section and (2) the linear energy storage section before the macroenergy evolution peak can be subdivided into two sections in the meso‐level energy evolution. Under uniaxial compression, the energy values at the characteristic points of the meso‐level energy evolution phases first asymmetrically decrease and then increase with the increase of the joint inclination. The initiation point of jointed sandstone is significantly affected by the length of the joint, and the degradation effect of the meso‐energy at the damage point and peak point weakens with the increase of the joint length. Comparing the data obtained from the PFC numerical simulation with the experimental data, it is found that the error is small, which shows the feasibility of the numerical model in this paper. Under biaxial compression, the accumulation rate of meso‐elastic strain at the peak point of the jointed sandstone first decreases and then increases with the joint inclination angle. After the peak of jointed sandstone, the rate of sudden change of meso‐energy change decreases with the increase of joint length. The conditions of high confining pressure will promote the meso‐accumulated damage degree of the jointed sandstone before the peak, while inhibiting the meso‐energy and the mutation degree of the damage after the peak. The higher the confining pressure, the more obvious the joint length and inclination effect characteristics of the elastic strain energy at the peak point of the jointed sandstone.

Latest Designing Principle on the Microstructure and Lattice-Structure for High-Energy-Density Antiferroelectric Materials in Fast Discharging Applications

Antiferroelectric (AFE) materials are considered to have a potentially ultrahigh energy density, which is a determinant for pulse capacitors used in the energy storage section of fast discharging a...

Design of a 1-MV induction cavity and validation of the two-dimensional circuit model

We present the design and test results of an induction cavity, which is a full-scale prototype cell of a prospective six-stage induction voltage adder. This induction cell runs in positive polarity and the output transmission line operates in the vacuum insulation state. The design methods and configurations of the azimuthal transmission line, insulation stack, magnetic core, cathode plate, and output transmission line in the induction cell are given in detail. The induction cavity is driven by one pulsed power system consisting of a tesla transformer, intermediate storage capacitor, laser triggered gas switch, pulse forming line, self-breaking oil switch, and a water transmission line. A maximum voltage about 1.05 MV could be achieved across one $7.0\text{ }\text{ }\mathrm{\ensuremath{\Omega}}$ water resistor load. A full circuit model including the primary energy storage section and pulse forming section is proposed. The circuit model also includes the two-dimensional circuit model of the induction cavity [Phys. Rev. Accel. Beams 20, 020401 (2017)]. The voltage and current waveforms across the feed port, azimuthal transmission line, insulation stack, and resistor load obtained during the experiment are compared with the circuit simulation results. It demonstrates that they can agree with each other very well.

Combining high energy efficiency and fast charge-discharge capability in novel BaTiO3-based relaxor ferroelectric ceramic for energy-storage

Compared with the other types of ceramic capacitors, relaxor ferroelectric ceramics demonstrate superior potential in energy-storage fields due to their higher energy efficiency, faster charge-discharge rate, and better temperature stability. In this study, we designed and synthesized a novel high performance BaTiO3-based ((1-x)BaTiO3-xBi(Ni2/3Nb1/3)O3, x = 0.08, 0.10, 0.12, and 0.14) energy-storing ceramics through ferroelectric properties modulation, which display typical relaxor characteristics. The optimum energy storage properties, i.e. ultrahigh energy efficiency (95.9%), high energy-storage density (2.09 J cm−3) and good temperature stability (the fluctuations in energy-storage properties are less than 5% over 20–120 °C) are obtained at x = 0.12 (0.88BT-0.12BNN). The 0.88BT-0.12BNN relaxor ferroelectric ceramic demonstrates obviously superior comprehensive energy-storage properties than most of other unleaded ceramics. Besides, investigation efforts were also spent on the pulsed charge-discharge performance of the 0.88BT-0.12BNN ceramic to evaluate its feasibility as energy-storage devices. More importantly, the 0.88BT-0.12BNN ceramic also exhibits outstanding charge-discharge performance with fast discharge rate (t0.9 < 100 ns), a high level of power density (36.9 MW cm−3), and good temperature stability. These excellent performance parameters qualify this novel and environmentally friendly BaTiO3-based ceramic as a promising alternative option in energy-storage section. Meanwhile, this study also provides an effective approach to attain high energy-storage density as well as energy efficiency in BaTiO3-based relaxor ferroelectric ceramics.

CSP-PT gas plant using air as Heat Transfer Fluid with a packed-bed storage section

Concentrated Solar Power technologies represent an important alternative able to replace in a medium/long term fossil fuel sources. Current technology has several drawbacks which prevent a large diffusion: the principal one is the choice of the Heat Transfer Fluid which involves a certain complexity, including the heat storage section. Conventional plants in operation, consider diathermic oil and, more recently, molten salts. The potential of gases as working fluid has been underestimated till now and its use has not still fully exploited. Using gas would determinate a simpler conversion section increasing reliability. The gas, as proposed by the authors, can expand directly in a series of inter-reheated turbines after a series of intercooled compressions, reaching an acceptable overall global efficiency of the conversion section. The paper describes the optimum choice for the thermodynamic cycle which approaches an Ericsson cycle, integrating it with a comprehensive mathematical model for the heating section of the gas inside the solar receiver. A Thermal Energy Storage section based on the use of a packed bed of rocks has been considered, merged at the plant to insure production continuity. The overall software platform for the plant can be used as design tool in order to set up most important alternatives related to the plant characteristics and specific parameters.

Investigation of a combined cycle power plant coupled with a parabolic trough solar field and high temperature energy storage system

This study was aimed at exergetically investigating a combined cycle power plant coupled with a parabolic trough solar field and high temperature energy storage system. Thermodynamic modeling of the combined cycle was conducted by ASPEN HYSYS simulation software, while the modeling of solar and energy storage section was carried out using MATLAB software. The main goal of the present research work was to reveal the reasons and sources of the thermodynamic losses occurring in the power plant based on the thermodynamic outcomes obtained from modeling. After writing the exergy balance equations for all the subunits of the power plant, their exergetic performance parameters were measured individually. Moreover, the effect of different influential parameters such as gas turbine inlet temperature and outlet pressure, and the R113 working fluid mass flow rate on the exergy and electrical efficiencies of the whole system was also investigated and scrutinized. The exergetic value of the net electric power was found to be 93,580 kW. The overall exergy destruction of the system stood at 216,710 kW. The contribution of solar and energy storage combination, as the main subunit wasting exergy, to the overall exergy destruction of the system was determined at 43%. Moreover, combustion chamber subunit stood in the next rank in terms of exergy destruction, contributing 15.7% of the overall exergy destruction of the power plant. The overall exergy efficiency and electrical efficiency of the power cycle was determined at 38.2% and 47%, respectively.

Application of Concentrating Solar Technologies in the Dairy Sector for the Combined Production of Heat and Power

Abstract The use of concentrating solar technologies for supplying the heat and power demand of a typical dairy factoryis investigated in this paper.A yearly-based performance analysis iscarried out considering different values of solar field collecting area and thermal energy storage capacity with reference to a typical meteorological data setof a Sardinian location. Specific simulation models are developed for each section of the plant. Moreover, a novel energy management strategy isdeveloped for the determination of the priority order between thermal and electrical demand. The results demonstrate that concentrating solar technologies could be a promising option if power and heat are both required. In particular, the presence of the energy storage section provides important flexibility features to the plant and by suitably setting the control variable, the energy management strategy allows to give priority to the heat or to the electrical demand of the dairy.

Battery development and testing at the European Space Agency

The principal activities of the Energy Storage Section of the Space Research and Technology Center (ESTEC) of the European Space Agency are presented. Nickel—hydrogen and fuel cell systems development are reported. The European Space Battery Test Center (ESBTC) facilities are briefly described along with the current test programs and results obtained.